Capture One offers a highly customizable mask when cropping. In the Capture One Preferences, under the Crop tab, note how the masked area outside the crop can be adjusted to your taste. By using the Opacity and Brightness sliders, it is possible to turn the mask into a fully black or white color or any tones within those two extremes. You can also choose whether you would like to always see the two labels showing the image dimensions, show them only while dragging the crop or never. This is done from the Show Labels drop-down menu.